fix(boatstack): prevent hallucinated approver names in plan approval

[bigboateng]

Why this change

Addresses the issue where Boatstack-managed delivery PRs incorrectly list "Sam" or "Eve" as the approver. This occurred because if the LLM failed to run the deterministic "gh api" command (due to sandbox or auth limits), it would fill the "" placeholder in "approval.md" with hallucinated common placeholder names like "Sam" or "Eve" instead of following the instruction to "ask one short identity follow-up".

What changed

• Added explicit prompt guidance to the Boatstack skill generator (export.go), as well as the template SKILL.md and workflow.md reference files, strictly forbidding the AI from inventing placeholder names (like Sam/Eve) and requiring it to ask the user when the identity is unresolved.
• Regenerated all 54 public-facing skill and adapter files to include this new prompt guidance.

Evidence

• All Go tests in "product-engineering-loop" passed successfully.
• All Python tests in "labs/12-product-engineering-loop/" passed successfully.